U.S. patent application number 11/538582 was filed with the patent office on 2007-05-10 for puncture resistant composite.
Invention is credited to Thomas E. Mabe, Yunzhang Wang.
Application Number | 20070105471 11/538582 |
Document ID | / |
Family ID | 37717732 |
Filed Date | 2007-05-10 |
United States Patent
Application |
20070105471 |
Kind Code |
A1 |
Wang; Yunzhang ; et
al. |
May 10, 2007 |
Puncture Resistant Composite
Abstract
A puncture resistant composite comprises a first textile layer
and a second textile layer, each of which comprises a plurality of
yarns or fibers having a tenacity of about 8 or more grams per
denier. The layers are stacked so that the upper surface of the
second textile layer is adjacent to the lower surface of the first
textile layer. At least one of the lower surface of the first
textile layer and the upper surface of the second textile layer
comprises about 10 wt. % or less, based on the total weight of the
textile layer, of a coating comprising a plurality of particles
having a diameter of about 20 .mu.m or less. The coating can also
comprise a binder. The composite can also be used in combination
with other puncture resistant and/or ballistic resistant materials
or components. A process for producing a puncture resistant
composite is also provided.
Inventors: |
Wang; Yunzhang; (Duncan,
SC) ; Mabe; Thomas E.; (Spartanburg, SC) |
Correspondence
Address: |
Legal Department (M-495)
P.O. Box 1926
Spartanburg
SC
29304
US
|
Family ID: |
37717732 |
Appl. No.: |
11/538582 |
Filed: |
October 4, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60727486 |
Oct 17, 2005 |
|
|
|
Current U.S.
Class: |
442/301 ;
428/902; 442/134; 442/239; 442/294 |
Current CPC
Class: |
F41H 5/0471 20130101;
B32B 2262/0269 20130101; Y10T 442/3919 20150401; B32B 2571/02
20130101; Y10T 442/2623 20150401; F41H 5/0492 20130101; Y10T
442/3472 20150401; A43B 13/12 20130101; Y10T 442/2615 20150401;
Y10T 442/3976 20150401; B32B 5/26 20130101; A43B 7/32 20130101;
A43B 13/026 20130101 |
Class at
Publication: |
442/301 ;
442/239; 442/134; 442/294; 428/902 |
International
Class: |
B32B 5/26 20060101
B32B005/26; B32B 27/04 20060101 B32B027/04; B32B 27/12 20060101
B32B027/12; B32B 5/16 20060101 B32B005/16 |
Claims
1. A puncture resistant composite comprising: (a) a first textile
layer comprising a plurality of yarns or fibers having a tenacity
of about 8 or more grams per denier, the first textile layer having
an upper surface and a lower surface, (b) a second textile layer
comprising a plurality of yarns or fibers having a tenacity of
about 8 or more grams per denier, the second textile layer having
an upper surface and a lower surface, the upper surface of the
second textile layer being adjacent to the lower surface of the
first textile layer, wherein at least one of the lower surface of
the first textile layer and the upper surface of the second textile
layer comprises about 10 wt. % or less, based on the total weight
of the textile layer, of a coating comprising a plurality of
particles having a diameter of about 20 .mu.m or less.
2. The puncture resistant composite of claim 1, wherein the
particles are selected from the group consisting of silica,
alumina, silicon carbide, titanium carbide, tungsten carbide,
titanium nitride, silicon nitride, and combinations thereof.
3. The puncture resistant composite of claim 2, wherein the
particles are selected from the group consisting of fumed alumina
and fumed silica.
4. The puncture resistant composite of claim 3, wherein the
particles comprise fumed alumina.
5. The puncture resistant composite of claim 1, wherein the
particles have a diameter of about 300 nm or less.
6. The puncture resistant composite of claim 1, wherein the coating
further comprises a binder.
7. The puncture resistant composite of claim 6, wherein the binder
comprises about 5 to about 15 wt. % of the coating.
8. The puncture resistant composite of claim 1, wherein the yarns
or fibers of the first and second textile layers comprise fibers
selected from the group consisting of gel-spun ultrahigh molecular
weight polyethylene fibers, melt-spun polyethylene fibers,
melt-spun nylon fibers, melt-spun polyester fibers, sintered
polyethylene fibers, aramid fibers, PBO fibers, PBZT fibers, PIPD
fibers, poly(6-hydroxy-2-napthoic acid-co-4-hydroxybenzoic acid)
fibers, carbon fibers, and combinations thereof.
9. The puncture resistant composite of claim 8, wherein the yarns
or fibers comprise aramid fibers.
10. The puncture resistant composite of claim 9, wherein the yarns
or fibers comprise poly-p-phenyleneterephthalamide fibers.
11. The puncture resistant composite of claim 1, wherein the yarns
or fibers have a tenacity of about 14 or more grams per denier.
12. The puncture resistant composite of claim 1, wherein the first
and second textile layers are woven fabrics comprising a plurality
of yarns.
13. The puncture resistant composite of claim 1, wherein the yarns
or fibers have a diameter of about 100 to about 1500 denier.
14. The puncture resistant composite of claim 1, wherein the first
and second textile layers have a weight of about 4 to about 10
ounces per square yard.
15. The puncture resistant composite of claim 1, wherein the
coating comprises about 5 wt. % or less of the total weight of the
first or second textile layer.
16. The puncture resistant composite of claim 1, wherein the
composite comprises a third textile layer comprising a plurality of
yarns or fibers having a tenacity of about 8 or more grams per
denier, the third textile layer having an upper surface and a lower
surface, the upper surface of the third textile layer being
adjacent to the lower surface of the second textile layer, wherein
at least one of the lower surface of the second textile layer and
the upper surface of the third textile layer comprises about 5 wt.
% or less, based on the total weight of the textile layer, of the
coating.
17. A process for producing a puncture resistant composite, the
process comprising the steps of: (a) providing a first textile
layer and a second textile layer, the first and second textile
layers each comprising a plurality of yarns or fibers having a
tenacity of about 8 or more grams per denier, and the first and
second textile layers each having an upper surface and a lower
surface, (b) contacting at least one of the lower surface of the
first textile layer and the upper surface of the second textile
layer with a coating composition comprising a plurality of
particles having a diameter of about 20 .mu.m or less and, (c)
drying the textile layer treated in step (b) to produce a coating
on the lower surface of the first textile layer or the upper
surface of the second textile layer, and (d) assembling the first
and second textile layers so that the lower surface of the first
textile layer is adjacent to the upper surface of the second
textile layer, thereby producing a puncture resistant
composite.
18. The process of claim 17, wherein the coating comprises about 10
wt. % or less of the total weight of the first or second textile
layer.
19. The process of claim 17, wherein the particles comprise fumed
alumina.
20. The process of claim 17, wherein the yarns or fibers of the
first and second textile layers comprise fibers selected from the
group consisting of gel-spun ultrahigh molecular weight
polyethylene fibers, melt-spun polyethylene fibers, melt-spun nylon
fibers, melt-spun polyester fibers, sintered polyethylene fibers,
aramid fibers, PBO fibers, PBZT fibers, PIPD fibers,
poly(6-hydroxy-2-napthoic acid-co-4-hydroxybenzoic acid) fibers,
carbon fibers, and combinations thereof.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application claims, under 35 U.S.C. .sctn.119(e), the
benefit of the filing date of copending, provisional U.S. Patent
Application No. 60/727,486, which was filed on Oct. 17, 2005.
FIELD OF THE INVENTION
[0002] The present application is directed to composites exhibiting
puncture resistant properties.
BRIEF SUMMARY OF THE INVENTION
[0003] The invention provides a puncture resistant composite
comprising (a) a first textile layer comprising a plurality of
yarns or fibers having a tenacity of about 8 or more grams per
denier, the first textile layer having an upper surface and a lower
surface, (b) a second textile layer comprising a plurality of yarns
or fibers having a tenacity of about 8 or more grams per denier,
the second textile layer having an upper surface and a lower
surface, the upper surface of the second textile layer being
adjacent to the lower surface of the first textile layer, wherein
at least one of the lower surface of the first textile layer and
the upper surface of the second textile layer comprises about 10
wt. % or less, based on the total weight of the textile layer, of a
coating comprising a plurality of particles having a diameter of
about 20 .mu.m or less. The puncture resistant composite according
to the invention can further comprise ballistic resistant materials
(e.g., ballistic resistant laminates) and/or puncture resistant
materials (e.g., chain mail, metal plating, or ceramic
plating).
[0004] The invention also provides a process for producing a
puncture resistant composite, the process comprising the steps of
(a) providing a first textile layer and a second textile layer, the
first and second textile layers each comprising a plurality of
yarns or fibers having a tenacity of about 8 or more grams per
denier, and the first and second textile layers each having an
upper surface and a lower surface, (b) contacting at least one of
the lower surface of the first textile layer and the upper surface
of the second textile layer with a coating composition comprising a
plurality of particles having a diameter of about 20 .mu.m or less,
(c) drying the textile layer treated in step (b) to produce a
coating on the lower surface of the first textile layer or the
upper surface of the second textile layer, and (d) assembling the
first and second textile layers so that the lower surface of the
first textile layer is adjacent to the upper surface of the second
textile layer, thereby producing a puncture resistant
composite.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a sectional view of a puncture resistant composite
according to the invention.
[0006] FIG. 2 is a perspective view of a personal protection
device, specifically a vest, incorporating the puncture resistant
composite of the invention.
[0007] FIG. 3 is a graph depicting the peak load versus the number
of layers for Samples 1A-1D and an untreated control.
[0008] FIG. 4 is a graph depicting the peak load versus the number
of layers for Sample 2A, Sample 2B and an untreated control.
[0009] FIG. 5 is scanning electron micrograph of the surface of
Sample 1B.
[0010] FIG. 6 is an exploded, perspective view of a ballistic
resistant laminate suitable for use in the composite of the
invention.
[0011] FIG. 7 is a sectional view of a puncture resistant composite
according to the invention, which includes a ballistic resistant
laminate such as that depicted in FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
[0012] The invention is directed to a puncture resistant composite.
As utilized herein, the term "puncture resistant" is generally used
to refer to a material that provides protection against penetration
of the material by, for example, knives, edged weapons, and
sharp-pointed weapons or objects. Thus, a "puncture resistant"
material can either prevent penetration of the material by such an
object or can lessen the degree of penetration of such an object as
compared to similar, non-puncture resistant materials. Preferably,
a "puncture resistant" material achieves a pass rating when tested
against Level 1, Spike class threats in accordance with National
Institute of Justice (NIJ) Standard 0115.00 (2000), entitled "Stab
Resistance of Personal Body Armor." The term "puncture resistant"
can also refer to materials (e.g., a composite according to the
invention) achieving a pass rating when tested against higher level
threats (e.g., Level 2 or Level 3) and/or other threat weapons
(e.g., Level 1 or higher P1 knife threats and/or Level 1 or higher
S1 knife threats) according to NIJ Standard 0115.00. In certain
possibly preferred embodiments, the invention can also be directed
to a puncture and ballistic resistant composite. As utilized
herein, the term "ballistic resistant" generally refers to a
material that is resistant to penetration by ballistic projectiles.
Thus, a "ballistic resistant" material can either prevent
penetration of the material by a ballistic projectile or can lessen
the degree of penetration of such ballistic projectiles as compared
to similar, non-ballistic resistant materials. Preferably, a
"ballistic resistant" material provides protection equivalent to
Type I body armor when such material is tested in accordance with
National Institute of Justice (NIJ) Standard 0101.04 (2000),
entitled "Ballistic Resistance of Personal Body Armor." The term
"ballistic resistant" also refers to a material that achieves a
pass rating when tested against Level 1 or higher (e.g., Level 2A,
Level 2, Level 3A, or Level 3 or higher) ballistic threats in
accordance with NIJ Standard 0101.04.
[0013] As noted above, the composite of the invention comprises a
first textile layer and a second textile layer. The first and
second textile layers can have any suitable construction. For
example, the first and second textile layers can comprise a
plurality of yarns provided in a knit or woven construction.
Alternatively, the first and second textile layers can comprise a
plurality of fibers provided in a suitable nonwoven construction
(e.g., a needle-punched nonwoven, an air-laid nonwoven, etc.). As
will be understood by those of ordinary skill in the art, the
textile layers of the composite can be independently provided in
each of the aforementioned suitable constructions. For example, the
first textile layer can comprise a plurality of yarns provided in a
woven construction, and the second textile layer can comprise a
plurality of fibers provided in a needle-punched nonwoven
construction. In certain possibly preferred embodiments, the first
and second textile layers comprise a plurality of yarns provided in
a woven construction. The first and second textile layers can have
any suitable weight. In certain possibly preferred embodiments, the
textile layers can have a weight of about 4 to about 10 ounces per
square yard.
[0014] The yarns or fibers of the first and second textile layers
can comprise any suitable fibers. Yarns or fibers suitable for use
in the textile layer generally include, but are not limited to,
high tenacity yarns or fibers, which refers to yarns that exhibit a
relatively high ratio of stress to strain when placed under
tension. In order to provide adequate protection against ballistic
projectiles, the yarns or fibers of the textile layers typically
have a tenacity of about 8 or more grams per denier. In certain
possibly preferred embodiments, the yarns or fibers of the first
and second textile layers can have a tenacity of about 14 or more
grams per denier.
[0015] Fibers suitable for use in the first and second textile
layers include, but are not limited to, fibers made from highly
oriented polymers, such as gel-spun ultrahigh molecular weight
polyethylene fibers (e.g., SPECTRA.RTM. fibers from Honeywell
Advanced Fibers of Morristown, N.J. and DYNEMA.RTM. fibers from DSM
High Performance Fibers Co. of the Netherlands), melt-spun
polyethylene fibers (e.g., CERTRAN.RTM. fibers from Celanese Fibers
of Charlotte, N.C.), melt-spun nylon fibers (e.g., high tenacity
type nylon 6,6 fibers from Invista of Wichita, Kans.), melt-spun
polyester fibers (e.g., high tenacity type polyethylene
terephthalate fibers from Invista of Wichita, Kans.), and sintered
polyethylene fibers (e.g., TENSYLON.RTM. fibers from ITS of
Charlotte, N.C.). Suitable fibers also include those made from
rigid-rod polymers, such as lyotropic rigid-rod polymers,
heterocyclic rigid-rod polymers, and thermotropic
liquid-crystalline polymers. Suitable fibers made from lyotropic
rigid-rod polymers include aramid fibers, such as
poly(p-phenyleneterephthalamide) fibers (e.g., KEVLAR.RTM. fibers
from DuPont of Wilmington, Del. and TWARON.RTM. fibers from Teijin
of Japan) and fibers made from a 1:1 copolyterephthalamide of
3,4'-diaminodiphenylether and p-phenylenediamine (e.g.,
TECHNORA.RTM. fibers from Teijin of Japan). Suitable fibers made
from heterocyclic rigid-rod polymers, such as p-phenylene
heterocyclics, include poly(p-phenylene-2,6-benzobisoxazole) fibers
(PBO fibers) (e.g., ZYLON.RTM. fibers from Toyobo of Japan),
poly(p-phenylene-2,6-benzobisthiazole) fibers (PBZT fibers), and
poly[2,6-diimidazo[4,5-b:4',5'-e]pyridinylene-1,4-(2,5-dihydroxy)phenylen-
e] fibers (PIPD fibers) (e.g., M5.RTM. fibers from DuPont of
Wilimington, Del.). Suitable fibers made from thermotropic
liquid-crystalline polymers include poly(6-hydroxy-2-napthoic
acid-co-4-hydroxybenzoic acid) fibers (e.g., VECTRAN.RTM. fibers
from Celanese of Charlotte, N.C.). Suitable fibers also include
carbon fibers, such as those made from the high temperature
pyrolysis of rayon, polyacrylonitrile (e.g., OPF.RTM. fibers from
Dow of Midland, Mich.), and mesomorphic hydrocarbon tar (e.g.,
THORNEL.RTM. fibers from Cytec of Greenville, S.C.). In certain
possibly preferred embodiments, the yarns or fibers of the textile
layers comprise fibers selected from the group consisting of
gel-spun ultrahigh molecular weight polyethylene fibers, melt-spun
polyethylene fibers, melt-spun nylon fibers, melt-spun polyester
fibers, sintered polyethylene fibers, aramid fibers, PBO fibers,
PBZT fibers, PIPD fibers, poly(6-hydroxy-2-napthoic
acid-co-4-hydroxybenzoic acid) fibers, carbon fibers, and
combinations thereof.
[0016] The yarns or fibers of the textile layers can have any
suitable weight per unit length (e.g., denier). Typically, the
yarns or fibers have a weight per unit length of about 50 to about
5,000 denier. In certain possibly preferred embodiments, the yarns
or fibers have a weight per unit length of about 100 to about 1,500
denier.
[0017] As depicted in FIG. 1, the first and second textile layers
are stacked to form the puncture resistant composite 100. The first
textile layer 102 has an upper surface 104 and a lower surface 106,
and the second textile layer 108 has an upper surface 110 and a
lower surface 112. As will be understood by those of ordinary skill
in the art, the surfaces of the textile materials have been labeled
for reference purposes only, and the designation of one surface as
an upper surface and another surface as a lower surface is not
intended to indicate the orientation of the technical face or
technical back of the textile layer. As noted above, the first and
second textile layers are stacked so that, for example, the lower
surface of the first textile layer is adjacent to the upper surface
of the second textile layer. As depicted in FIG. 1, the puncture
resistant composite can comprise, in certain embodiments, a third
textile layer 114. The third textile layer 114 can be positioned
either above the first textile layer 102 or below the second
textile layer 103. In FIG. 1, the third textile layer 114 has an
upper surface 116 and a lower surface 118, and the third textile
layer 114 is positioned so that the upper surface 116 of the third
textile layer 114 is adjacent to the lower surface 112 of the
second textile layer 108.
[0018] While the composite has been depicted in FIG. 1 as including
three textile layers, those of ordinary skill in the art will
readily appreciate that the composite can comprise any suitable
number of textile layers. For example, the puncture resistant
composite can comprise four textile layers, six textile layers,
eight textile layers, twelve textile layers, sixteen textile
layers, twenty textile layers, thirty textile layers, or forty
textile layers.
[0019] In order to impart puncture resistance to the composite, at
least one of the textile layers comprises a coating on a surface
thereof. Typically, the coating is applied to a surface of the
textile layer that is adjacent to another textile layer. Thus, as
depicted in FIG. 1, the coating 120 can be applied to the lower
surface 106 of the first textile layer 102. The coating 120 can
also be applied to the upper surface 110 of the second textile
layer 108. While not wishing to be bound to any particular theory,
it is believed that coating both of the adjacent surfaces of the
textile layers will increase the puncture resistance of the
resulting composite. In embodiments comprising more than two
textile layers, such as that depicted in FIG. 1, the coating 120
can be applied to the lower surface 112 of the second textile layer
108 and the upper surface 116 of the third layer 114. As will be
understood by those of ordinary skill in the art, the coating can
also be applied to those surfaces of the textile layers which are
not adjacent to a surface of another textile layer. For example, as
shown in FIG. 1, the coating 120 can be applied to the upper
surface 104 of the first textile layer 102 and the lower surface
118 of the third textile layer 114. Moreover, in certain possibly
preferred embodiments, the coating can also penetrate into the
interior portion of the textile layer(s) to at least partially coat
the yarns or fibers of the textile layer.
[0020] The coating applied to the textile layer(s) comprises
particulate matter (e.g., a plurality of particles). The particles
included in the coating can be any suitable particles, but
preferably are particles having a diameter of about 20 .mu.m or
less, or about 10 .mu.m or less, or about 1 .mu.m or less (e.g.,
about 500 nm or less or about 300 nm or less). Particles suitable
for use in the coating include, but are not limited to, silica
particles, (e.g., fumed silica particles, precipitated silica
particles, alumina-modified colloidal silica particles, etc.),
alumina particles (e.g. fumed alumina particles), and combinations
thereof. In certain possibly preferred embodiments, the particles
are comprised of at least one material selected from the group
consisting of fumed silica, precipitated silica, fumed alumina,
alumina modified silica, zirconia, titania, silicon carbide,
titanium carbide, tungsten carbide, titanium nitride, silicon
nitride, and the like, and combinations thereof. Such particles can
also be surface modified, for instance by grafting, to change
surface properties such as charge and hydrophobicity. Suitable
commercially available particles include, but are not limited to,
the following: CAB-O-SPERSE.RTM. PG003 fumed alumina, which is a
40% by weight solids aqueous dispersion of fumed alumina available
commercially from Cabot Corporation of Boyertown, Pa. (the
dispersion has a pH of 4.2 and a median average aggregate particle
size of about 150 nm); SPECTRAL.TM. 51 fumed alumina, which is a
fumed alumina powder available commercially from Cabot Corporation
of Boyertown, Pa. (the powder has a BET surface area of 55
m.sup.2/g and a median average aggregate particle size of about 150
nm); CAB-O-SPERSE.RTM. PG008 fumed alumina, which is a 40% by
weight solids aqueous dispersion of fumed alumina available
commercially from Cabot Corporation of Boyertown, Pa. (the
dispersion has a pH of 4.2 and a median average aggregate particle
size of about 130 nm); SPECTRAL.TM. 81 fumed alumina, which is a
fumed alumina powder available commercially from Cabot Corporation
of Boyertown, Pa. (the powder has a BET surface area of 80
m.sup.2/g and a median average aggregate particle size of about 130
nm); AEROXIDE ALU C fumed alumina, which is a fumed alumina powder
available commercially from Degussa, Germany (the powder has a BET
surface area of 100 m.sup.2/g and a median average primary particle
size of about 13 nm); LUDOX CL-P colloidal alumina coated silica,
which is a 40% by weight solids aqueous sol available from Grace
Davison (the sol has a pH of 4 and an average particle size of 22
nm in diameter); NALCO 1056 aluminized silica, which is a 30% by
weight solids aqueous colloidal suspension of aluminized silica
particles (26% silica and 4% alumina) available commercially from
Nalco; LUDOX TMA colloidal silica, which is a 34% by weight solids
aqueous colloidal silica sol available from Grace Davison. (the sol
has a pH of 4.7 and an average particle size of 22 nm in diameter);
NALCO 88SN-126 colloidal titanium dioxide, which is a 10% by weight
solids aqueous dispersion of titanium dioxide available
commercially from Nalco; CAB-O-SPERSE.RTM. S3295 fumed silica,
which is a 15% by weight solids aqueous dispersion of fumed silica
available commercially from Cabot Corporation of Boyertown, Pa.
(the dispersion has a pH of 9.5 and an average agglomerated primary
particle size of about 100 nm in diameter); CAB-O-SPERSE.RTM. 2012A
fumed silica, which is a 12% by weight solids aqueous dispersion of
fumed silica available commercially from Cabot Corporation of
Boyertown, Pa. (the dispersion has a pH of 5); CAB-O-SPERSE.RTM.
PG001 fumed silica, which is a 30% by weight solids aqueous
dispersion of fumed silica available commercially from Cabot
Corporation of Boyertown, Pa. (the dispersion has a pH of 10.2 and
a median aggregate particle size of about 180 nm in diameter);
CAB-O-SPERSE.RTM. PG002 fumed silica, which is a 20% by weight
solids aqueous dispersion of fumed silica available commercially
from Cabot Corporation of Boyertown, Pa. (the dispersion has a pH
of 9.2 and a median aggregate particle size of about 150 nm in
diameter); CAB-O-SPERSE.RTM. PG022 fumed silica, which is a 20% by
weight solids aqueous dispersion of fumed silica available
commercially from Cabot Corporation of Boyertown, Pa. (the
dispersion has a pH of 3.8 and a median aggregate particle size of
about 150 nm in diameter); SIPERNAT 22LS precipitated silica, which
is a precipitated silica powder available from Degussa of Germany
(the powder has a BET surface area of 175 m.sup.2/g and a median
average primary particle size of about 3 .mu.m); SIPERNAT 500LS
precipitated silica, which is a precipitated silica powder
available from Degussa of Germany (the powder has a BET surface
area of 450 m.sup.2/g and a median average primary particle size of
about 4.5 .mu.m); and VP Zirconium Oxide fumed zirconia, which is a
fumed zirconia powder available from Degussa of Germany (the powder
has a BET surface area of 60 m.sup.2/g).
[0021] In certain possibly preferred embodiments, the particles can
have a positive surface charge when suspended in an aqueous medium,
such as an aqueous medium having a pH of about 4 to 8. Particles
suitable for use in this embodiment include, but are not limited
to, alumina-modified colloidal silica particles, alumina particles
(e.g. fumed alumina particles), and combinations thereof. In
certain possibly preferred embodiments, the particles can have a
Mohs' hardness of about 5 or more, or about 6 or more, or about 7
or more. Particles suitable for use in this embodiment include, but
are not limited to, fumed alumina particles. In certain possibly
preferred embodiments, the particles can have a three-dimensional
branched or chain-like structure comprising or consisting of
aggregates of primary particles. Particles suitable for use in this
embodiment include, but are not limited to, fumed alumina
particles, fumed silica particles, and combinations thereof.
[0022] The particles included in the coating can be modified to
impart or increase the hydrophobicity of the particles. For
example, in those embodiments comprising fumed silica particles,
the fumed silica particles can be treated, for example, with an
organosilane in order to render the fumed silica particles
hydrophobic. Suitable commercially-available hydrophobic particles
include, but are not limited to, the R-series of AEROSIL.RTM. fumed
silicas available from Degussa, such as AEROSIL.RTM. R812,
AEROSIL.RTM. R816, AEROSIL.RTM. R972, and AEROSIL.RTM. R7200. While
not wishing to be bound to any particular theory, it is believed
that using hydrophobic particles in the coating will minimize the
amount of water that the composite will absorb when exposed to a
wet environment. When hydrophobic particles are utilized in the
coating on the textile layer(s), the hydrophobic particles can be
applied using a solvent-containing coating composition in order to
assist their application.
[0023] The textile layer(s) can comprise any suitable amount of the
coating. As will be understood by those of ordinary skill in the
art, the amount of coating applied to the layer(s) generally should
not be so high that the weight of the composite is dramatically
increased, which could potentially impair certain end uses for the
composite. Typically, the amount of coating applied to the textile
layer(s) will comprise about 10 wt. % or less of the total weight
of the textile layer. In certain possibly preferred embodiments,
the amount of coating applied to the textile layer(s) will comprise
about 5 wt. % or less or about 3 wt. % or less (e.g., about 2 wt. %
or less) of the total weight of the textile layer. Typically, the
amount of coating applied to the textile layer(s) will comprise
about 0.1 wt. % or more (e.g., about 0.5 wt. % or more) of the
total weight of the textile layer. In certain possibly preferred
embodiments, the coating comprises about 2 to about 4 wt. % of the
total weight of the textile layer.
[0024] In certain possibly preferred embodiments of the composite,
the coating applied to the textile layer can further comprise a
binder. The binder included in the coating can be any suitable
binder. Suitable binders include, but are not limited to,
isocyanate binders (e.g., blocked isocyanate binders), acrylic
binders (e.g, nonionic acrylic binders), polyurethane binders
(e.g., aliphatic polyurethane binders and polyether based
polyurethane binders), epoxy binders, and combinations thereof. In
certain possibly preferred embodiments, the binder is a
cross-linking binder, such as a blocked isocyanate binder.
[0025] When present, the binder can comprise any suitable amount of
the coating applied to the textile layer(s). The ratio of the
amount (e.g., weight) of particles present in the coating to the
amount (e.g., weight) of binder solids present in the coating
typically is greater than about 1:1 (weight particles: weight
binder solids). In certain possibly preferred embodiments, the
ratio of the amount (e.g., weight) of particles present in the
coating to the amount (e.g., weight) of binder solids present in
the coating typically is greater than about 2:1, or greater than
about 3:1, or greater than about 4:1, or greater than about 5:1
(e.g., greater than about 6:1, greater than about 7:1, or greater
than about 8:1).
[0026] In certain possibly preferred embodiments, the coating
applied to the textile layer(s) can comprise a water-repellant in
order to impart greater water repellency to the composite. The
water-repellant included in the coating can be any suitable
water-repellant including, but not limited to, fluorochemicals or
fluoropolymers.
[0027] As noted above, the composite can comprise any suitable
number of textile layers (e.g., four textile layers, six textile
layers, eight textile layers, twelve textile layers, sixteen
textile layers, or twenty textile layers). Furthermore, any
suitable number of the textile layers can have the above-described
coating applied thereto. For example, each textile layer of the
composite can have the coating applied to one or both of its
surfaces. Alternatively, the composite can comprise an alternating
series of coated and uncoated textile layers. In such an
embodiment, the composite can comprise, for example, a first series
of ten coated textile layers and a second series of ten uncoated
textile layers disposed adjacent to the first series of textile
layers. Each of these coated and uncoated textile layers can be any
of the suitable textile layers described above.
[0028] The composite of the invention preferably does not exhibit
any substantial change in flexibility as compared to similar,
uncoated materials. In particular, the textile layers of the
composite preferably exhibit the same or substantially similar
flexibility as compared to similar, uncoated textile materials.
[0029] The puncture resistant composite can be produced by any
suitable method or process; however, the invention also provides a
process for producing the composite. In particular, the process
comprises the steps of (a) providing a first textile layer and a
second textile layer, (b) contacting at least one of the lower
surface of the first textile layer and the upper surface of the
second textile layer with a coating composition comprising a
plurality of particles having a diameter of about 20 .mu.m or less,
(c) drying the textile layer treated in step (b) to produce a
coating on the lower surface of the first textile layer or the
upper surface of the second textile layer, and (d) assembling the
first and second textile layers so that the lower surface of the
first textile layer is adjacent to the upper surface of the second
textile layer, thereby producing a puncture resistant
composite.
[0030] The first and second textile layers suitable for use in the
above-described method include, but are not limited to, those
materials described above as being suitable for use in the
composite. Also, the coating compositions suitable for used in the
method include, but are not limited to, those compositions
containing the particles and, optionally, binders described above
as being suitable for use in the coating on the textile layer(s) of
the composite. Typically, a coating composition suitable for use in
the above-described method comprises an aqueous dispersion of the
particles and, optionally, a binder.
[0031] The surface(s) of the textile layer(s) can be contacted with
the coating composition in any suitable manner. The textile layers
can be contacted with the coating composition using convention
padding, spraying (wet or dry), foaming, printing, coating, and
exhaustion techniques. For example, the textile layer(s) can be
contacted with the coating composition using a padding technique in
which the textile layer is immersed in the coating composition and
then passed through a pair of nip rollers to remove any excess
liquid. In such an embodiment, the nip rollers can be set at any
suitable pressure, for example, at a pressure of about 280 kPa (40
psi). Alternatively, the surface of the textile layer to be coated
can be first coated with a suitable adhesive, and then the
particles can be applied to the adhesive.
[0032] The coated textile layer(s) can be dried using any suitable
technique at any suitable temperature. For example, the textile
layer(s) can be dried on a conventional tenter frame or range at a
temperature of about 160.degree. C. (320.degree. F.) for
approximately five minutes.
[0033] The first and second textile layers can be assembled using
any suitable technique. For example, as noted above, the first and
second textile layers can be stacked so that the coated surface of
the first or second textile layer is adjacent to the surface of the
other textile layer. In certain possibly preferred embodiments the
first and second textile layers can also be sewn together in a
desired pattern, for example, around the perimeter of the stacked
textile layers in order to secure the layers in the proper or
desired arrangement.
[0034] The puncture resistant composite of the invention and the
composite produced by the above-described process are particularly
well suited for use in personal protection devices, such as
personal body armor. For example, as depicted in FIG. 2, the
puncture resistant composite 202 can be incorporated into a vest
200 in order to provide the wearer protection against stab and, in
certain embodiments, ballistic threats.
[0035] The puncture resistant composite of the invention can
further comprise known ballistic resistant materials or components
in addition to the above-described textile layers. An example of a
known ballistic resistant material suitable for use in the
composite of the invention is the ballistic resistant laminate
depicted in FIG. 6. The laminate 600 comprises a first layer 610 of
substantially parallel fiber bundles 612 and a second layer 620 of
substantially parallel fiber bundles 622. The fibers suitable for
use in the fiber bundles 612, 614 can be any of the fibers
discussed above as being suitable for use in the textile layers of
the composite of the invention, including any suitable combinations
of such fibers. The fiber bundles 612, 614 typically are arranged
in one or more tiers within the first and second layers 610, 620
and in such a manner that each of the fiber bundles 612, 614 within
a layer 610, 620 is substantially parallel to the other fiber
bundles 612, 614 within the same layer (e.g., the fiber bundles
612, 614 within each layer 610, 620 are unidirectionally-oriented).
The fiber bundles 612, 614 within the first and second layers 610,
620 are at least partially coated with a resin 614, 624 in order to
maintain the fiber bundles 612, 614 within each layer 610, 620 in
their substantially parallel orientation.
[0036] The first layer 610 and the second layer 620 are stacked so
that the fiber bundles 612 within the first layer 610 are oriented
in a non-parallel relation relative to the fiber bundles 622 within
the second layer 620. While the laminate depicted in FIG. 6 is
shown with the fiber bundles 612 within the first layer 620
disposed at an angle of about 90 degrees relative to the fiber
bundles 622 within the second layer 620, the fiber bundles can be
disposed at any suitable angle between 0 and 180 degrees relative
to each other. However, the angle between the fibers 612 within the
first layer 610 and the fiber bundles 622 within the second layer
620 preferably is about 90 degrees.
[0037] The laminate 600 also comprises first and second
thermoplastic films 630, 640 disposed on the outer surfaces of the
first and second layers 610, 620 so that the first and second
layers 610, 620 are enclosed within an envelope formed by the films
630, 640.
[0038] While the laminate 600 depicted in FIG. 6 is shown with only
a first layer 610 and a second layer 620, the laminate can comprise
any suitable number of layers (i.e., layers of substantially
parallel fiber bundles) stacked atop each other. In such an
embodiment, the fiber bundles within adjacent layers typically are
disposed at any suitable angle between 0 and 180 degrees relative
to each other, with 90 degrees being preferred. Typically, the
layers are stacked so that the fiber bundles within a specific
layer are disposed at angle of about 90 degrees relative to the
fiber bundles in the layer immediately above and/or immediately
below that specific layer.
[0039] Commercially-available, ballistic resistant laminates such
as those described above include, but are not limited to, the
SPECTRA SHIELD.RTM. high-performance ballistic materials sold by
Honeywell International Inc. Such ballistic resistant laminates are
believed to be more fully described in U.S. Pat. No. 4,916,000 (Li
et al.); U.S. Pat. No. 5,437,905 (Park); U.S. Pat. No. 5,443,882
(Park); U.S. Pat. No. 5,443,883 (Park); and U.S. Pat. No. 5,547,536
(Park), each of which is herein incorporated by reference.
[0040] As shown in FIG. 7, a puncture resistant composite 700
according to the invention can comprise a ballistic resistant
laminate 600 in combination with the textile layers 102, 108, 114,
as described above. The laminate is disposed adjacent to the upper
or lower surface of one of the textile layers. The laminate can be
attached to the adjacent textile layer using any suitable means,
such as an adhesive, stitches, or other suitable mechanical
fasteners, or the laminate and textile layers can be disposed
adjacent to each other and held in place relative to each other by
a suitable enclosure, such as a pocket in a piece of body armor
which is adapted to carry a ballistic resistant insert.
[0041] A puncture resistant composite according to the invention
can further comprise other puncture resistant materials or
components. Examples of suitable known puncture resistant materials
or components include, but are not limited to, mail (e.g., chain
mail), metal plating, ceramic plating, or layers of textile
materials made from high tenacity yarns which layers have been
impregnated or laminated with an adhesive or resin. Such puncture
resistant materials or components can be attached to the adjacent
textile layer using any suitable means, such as an adhesive,
stitches, or other suitable mechanical fasteners, or the material
or component and textile layers can be disposed adjacent to each
other and held in place relative to each other by a suitable
enclosure, such as a pocket in a piece of body armor which is
adapted to carry a ballistic resistant insert.
[0042] A puncture resistant composite according to the invention
can further comprise one or more layers of suitable backing
material, such as a textile material (e.g., a textile material made
from any suitable natural or synthetic fiber), foam, or one or more
plastic sheets (e.g., polycarbonate sheets). For example, the
backing material can comprise a plurality of layers of woven or
knit polyester textile material which are positioned adjacent to
the upper or lower surface of the above-described textile layers.
The backing material can also be a trauma pack (e.g., one or more
polycarbonate sheets), such as those typically used in body
armor.
[0043] The following examples further illustrate the invention but,
of course, should not be construed as in any way limiting its
scope.
[0044] The samples in the Examples set forth below were treated
using a "padding" process, wherein a liquid coating is applied to a
textile substrate by passing the substrate through a bath and
subsequently through squeeze rollers. In particular, a piece of
fabric measuring approximately 13 inches (33 cm).times.17 inches
(43 cm) was immersed in a bath containing the chemical composition
containing the desired chemical agents. Unless otherwise stated,
all chemical percents (%) are percent by weight based on the total
weight of the bath prepared and the balance remaining, when
chemical percents or grams of chemical are given, is comprised of
water. In addition, the percent chemical was based on the chemical
as received from the manufacturer, such that if the composition
contained 30% active component, then X % of this 30% composition
was used.
[0045] After the fabric was completely wet by immersion in the
bath, the fabric was removed from the treatment bath and passed
between nip rolls (squeeze rolls) at a pressure of about 40 psi
(280 kPa) to obtain a uniform pickup generally between about 30%
and about 100%, based on the weight of the fabric. The fabric was
then pulled taut and pinned to a frame to retain the desired
dimensions. The pin frame was placed into a Despatch oven at a
temperature of between about 300.degree. F. (150.degree. C.) and
about 320.degree. F. (160.degree. C.) for between about 5 and about
8 minutes to dry and to cure the finish. Once removed from the
oven, the fabric was removed from the pin frame and allowed to
equilibrate at room temperature for at least 24 hours prior to
testing.
[0046] Two types of KEVKAR.RTM. fabric were used in the Examples
set forth below. One was a woven KEVLAR.RTM. KM-2 fabric obtained
from Hexcel Corporation of Arlington, Tex. The fabric was comprised
of KEVLAR.RTM. KM-2 850 denier warp and fill yarns woven together
in a plain weave construction with 31.5 ends/inch (12.4 ends/cm)
and 31 picks/inch (12.2 picks/cm). The fabric weight was
approximately 6.8 oz/yd.sup.2 (160 g/m.sup.2). The other fabric was
a woven KEVLAR.RTM. fabric from an actual ballistic vest (from
Safariland of Ontario, Calif.). The vest consists of 10 layers of
film backed laid-scrim type non-woven fabric and 17 layers of woven
KEVLAR.RTM. fabric with 750 denier yarns in a 31 ends/inch (12.2
ends/cm) by 31 picks/inch (12.2 picks/cm) plain weave construction.
The fabric weight of the woven fabric was approximately 6.2
oz/yd.sup.2 (150 g/m.sup.2). The vest was rated NIJ Threat Level
III-A.
[0047] A dynamic spike stab test was performed on the samples
according to NIJ Standard-0115.00, entitled "Stab Resistance of
Personal Body Armor" (September 2000). In this test, multiple
layers of test fabric are placed on a slab of backing materials
specified by the NIJ Standard. The backing materials were obtained
from BCF Foam Corporation of Hamilton, Ohio. The backing materials
consisted of four layers of 5.8 mm-thick neoprene sponge, followed
by one layer of 31-mm-thick polyethylene foam, and two 6.4-mm-thick
layers of rubber. The NIJ specified spike, which was obtained from
Precision Machine Works, Inc. of Culpeper, Va., was used as the
threat weapon. The spike was affixed to a NIJ specified drop mass
and dropped from a predetermined height inside a guided rail drop
tube at 0.degree. angle of incidence. The impact energy can be
varied by varying the drop speed. The depth of penetration is then
measured.
[0048] The quasi-static puncture test was performed using a MTS
Sintech 10/G tensile tester with a 562 lbs (255 kg) load cell used
in the compression mode. The compression speed is set at 1
inch/minute (2.5 cm/minute). In the quasi-static puncture test, the
same backing materials and spike specified for the dynamic spike
stab test were used. The spike is reinforced by a metal sleeve to
prevent it from bending. In this test, a predetermined number of
layers (typically 1, 2, 4, and 6 layers) of test fabric were placed
on the slab of backing materials and the spike is lowered into the
fabric at 1 inch/minute (2.5 cm/minute). The load and the
compression distance are recorded. At least three independent
measurements are performed for each test configuration. The peak
load (the force (in pounds) that is required to fully penetrate the
test sample) for each test configuration is then obtained.
EXAMPLE 1
[0049] Four samples (Samples 1A-1D) were produced by coating the
woven KEVLAR.RTM. KM-2 fabrics described above. Sample 1A was
prepared by coating the fabric in a bath comprising approximately
100 grams (or 10%) of CAB-O-SPERSE.RTM. PG003, a fumed alumina
dispersion (40% solids) with 150 nm particle size available from
Cabot Corporation, and approximately 900 grams of water. Sample 1B
was prepared by coating the fabric in a bath comprising
approximately 100 grams (or 10%) of CAB-O-SPERSE.RTM. PG003, 10
grams (or 1%) MILLITEX.TM. Resin MRX, a blocked isocyanate based
cross-linking agent (with 3545% solids) available from Milliken
Chemical, and 890 grams of water. Sample 1C was prepared by coating
the fabric in a bath comprising approximately 100 grams (or 10%) of
CAB-O-SPERSE.RTM. PG003, 20 grams (or 2%) MILLITEX.TM. Resin MRX,
and 880 grams of water. Sample 1D was prepared by coating the
fabric in a bath comprising approximately 100 grams (or 10%) of
CAB-O-SPERSE.RTM. PG003, 100 grams (or 10%) MILLITEX.TM. Resin MRX,
and 800 grams of water.
[0050] The treated KEVLAR.RTM. fabrics and the non-treated control
KEVLAR.RTM. fabric were tested for quasi-static spike puncture
resistance according to the procedures described above. The
quasi-static test results are shown in FIG. 3. The treated
KEVLAR.RTM. fabrics in Example 1B and the control fabrics were also
tested for dynamic spike stab resistant according to NIJ
Standard-0115.00. While 10 layers of the control fabric showed full
penetration (>70 mm), 10 layers of treated KEVLAR.RTM. fabric
(Example 1B) showed no visible signs of penetration and bent the
spike at 32 Joules of strike energy.
EXAMPLE 2
[0051] Two samples (Samples 2A and 2B) were produced by coating
woven KEVLAR.RTM. KM-2 fabrics as described above. Sample 2A was
prepared by coating the fabric in a bath comprising approximately
100 grams (or 10%) of LUDOX CL-P, a colloidal alumina-coated silica
sol (40% solids) with 22 nm particle size available from Grace
Davison, and approximately 900 grams of water. Sample 2B was
prepared by coating the fabric in a bath comprising approximately
120 grams (or 12%) of LUDOX TMA, a colloidal silica sol (34%
solids) with 22 nm particle size available from Grace Davison, and
approximately 880 grams of water.
[0052] The treated KEVLAR.RTM. fabrics and the non-treated control
KEVLAR.RTM. fabric were tested for quasi-static spike puncture
resistance according to the procedures described above. The test
results are shown in FIG. 4.
EXAMPLE 3
[0053] Three samples (Samples 3A-3C) were produced by coating the
woven KEVLAR.RTM. KM-2 fabrics described above. Sample 3A was
prepared by coating the fabric in a bath comprising approximately
100 grams (or 10%) of CAB-O-SPERSE.RTM. PG003, approximately 10
grams (or 1%) WITCOBOND W293, a polyurethane based binder (66-69%
solids) available from Crompton Corp., and approximately 890 grams
of water. Sample 3B was prepared by coating the fabric in a bath
comprising approximately 100 grams (or 10%) of CAB-O-SPERSE.RTM.
PG003, approximately 10 grams (or 1%) PRINTRITE 595, a nonionic
acrylic emulsion (45% solids) available from Noveon, and
approximately 890 grams of water. Sample 3C was prepared by coating
the fabric in a bath comprising approximately 100 grams (or 10%) of
CAB-O-SPERSE.RTM. PG003, approximately 10 grams (or 1%) SANCURE
898, a polyether based polyurethane dispersion (32% solids)
available from Noveon, and approximately 890 grams of water.
[0054] The treated KEVLAR.RTM. fabrics were tested for quasi-static
spike puncture resistance according to the procedures described
above. The test results are shown in Table 1. TABLE-US-00001 TABLE
1 Results of quasi-static spike puncture test for Samples 1B, 3A-C,
and Control. Peak Load (in lbs) Number of Sample layers Sample 1B
Sample 3A 3B Sample 3C Control 1 9.27 7.83 8.50 8.18 5.33 2 15.37
13.70 13.21 13.51 5.56 4 62.34 32.48 45.49 50.47 7.01 6 203.23
181.57 216.82 198.19 8.68
EXAMPLE4
[0055] Two samples (Samples 4A and 4B) were produced by coating
woven KEVLAR.RTM. KM-2 fabrics as described above. Sample 4A was
prepared by coating the fabric in a bath comprising approximately
100 grams (or 10%) of CAB-O-SPERSE.RTM. PG008, a fumed alumina
dispersion (40% solids) with 130 nm particle size available from
Cabot Corporation, approximately 10 grams (or 1%) MILLITEX.TM.
Resin MRX, and approximately 890 grams of water. Sample 4B was
prepared by coating the fabric in a bath comprising approximately
40 grams (or 4%) of AEROXIDE ALU C, a fumed alumina powder with 13
nm primary particle size available from Degussa, approximately 10
grams (or 1%) MILLITEX.TM. Resin MRX, and approximately 950 grams
of water.
[0056] The treated KEVLAR.RTM. fabrics were tested for quasi-static
spike puncture resistance according to the procedures described
above. The test results are shown in Table 2. TABLE-US-00002 TABLE
2 Results of quasi-static spike puncture test for Samples 1B, 4A,
4B, and Control. Number of Peak Load (in lbs) layers Sample 1B
Sample 4A Sample 4B Control 1 9.27 8.22 8.34 5.33 2 15.37 12.82
12.74 5.56 4 62.34 32.12 27.96 7.01 6 203.23 146.60 140.56 8.68
EXAMPLE 5
[0057] Sample 5 was prepared in the same manner as Sample 1B above,
except that the KEVLAR.RTM. KM-2 fabric was replaced with the woven
KEVLAR.RTM. fabric from an actual ballistic vest as described
above. The woven fabrics from the vest were removed from the vest,
and individual pieces of fabric were treated as in Example 1B.
[0058] The treated woven vest KEVLAR.RTM. fabrics and the
non-treated control woven vest KEVLAR.RTM. fabrics were tested for
quasi-static spike puncture resistance according to the procedures
described above. The quasi-static test results are shown in Table
3. TABLE-US-00003 TABLE 3 Results of quasi-static spike puncture
test for Sample 5 and Control. Peak Load (in lbs) Number of layers
Sample 5 Control 1 8.34 4.15 2 12.74 4.29 4 27.96 4.30 6 140.56
4.56
[0059] The treated vest KEVLAR.RTM. and the control fabrics were
also tested for dynamic spike stab resistant according to NIJ
Standard-0115.00. While 10 layers of the control fabric showed full
penetration (>70 mm), 8 layers of treated vest KEVLAR.RTM.
fabric showed no visible signs of penetration and bent the spike at
33 Joules of spike energy, and 10 layers of treated vest
KEVLAR.RTM. fabric showed no visible signs of penetration and bent
the spike at 60 Joules of strike energy.
[0060] The treated vest KEVLAR.RTM. fabrics were reassembled into
the original vest configuration (without sewing) and tested for
ballistic resistance at Level III-A according to NIJ Standard
0101.04 (2000). Within the experimental error, no significant
difference in performance was observed between the treated vest and
the control vest (without sewing). Both vests passed the Level
III-A test.
EXAMPLE 6
[0061] Four samples (Samples 6A-6D) were produced by coating the
woven KEVLAR.RTM. KM-2 fabrics described above. Sample 6A was
prepared by coating the fabric in a bath comprising approximately
333 grams (or 33.3%) of CAB-O-SPERSE.RTM. 2012A, a fumed silica
dispersion (12% solids) available from Cabot Corporation, and
approximately 667 grams of water. Sample 6B was prepared by coating
the fabric in a bath comprising approximately 333 grams (or 33.3%)
of CAB-O-SPERSE.RTM. 2012A, approximately 10 grams (or 1%)
MlLLITEX.TM. Resin MRX, and approximately 657 grams of water.
Sample 6C was prepared by coating the fabric in a bath comprising
approximately 200 grams (or 20%) of CAB-O-SPERSE.RTM. PG022, a
fumed silica dispersion (20% solids) available from Cabot
Corporation, and approximately 800 grams of water. Sample 6D was
prepared by coating the fabric in a bath comprising approximately
200 grams (or 20%) of CAB-O-SPERSE.RTM. PG022, approximately 10
grams (or 1%) MILLITEX.TM. Resin MRX, and approximately 790 grams
of water.
[0062] The treated KEVLAR.RTM. fabrics were tested for quasi-static
spike puncture resistance according to the procedures described
above. The tests results are shown in Table 4. TABLE-US-00004 TABLE
4 Results of quasi-static spike puncture test for Samples 6A-D, and
Control. Peak Load (in lbs) Number of Sample layers Sample 6A
Sample 6B 6C Sample 6D Control 1 9.21 9.30 11.06 9.27 5.33 2 17.10
17.17 21.04 17.96 5.56 4 147.99 77.75 140.36 133.21 7.01 6 271.65
258.08 269.76 236.72 8.68
[0063] All references, including publications, patent applications,
and patents, cited herein are hereby incorporated by reference to
the same extent as if each reference were individually and
specifically indicated to be incorporated by reference and were set
forth in its entirety herein.
[0064] The use of the terms "a" and "an" and "the" and similar
referents in the context of describing the invention (especially in
the context of the following claims) are to be construed to cover
both the singular and the plural, unless otherwise indicated herein
or clearly contradicted by context. The terms "comprising,"
"having," "including," and "containing" are to be construed as
open-ended terms (i.e., meaning "including, but not limited to,")
unless otherwise noted. Recitation of ranges of values herein are
merely intended to serve as a shorthand method of referring
individually to each separate value falling within the range,
unless otherwise indicated herein, and each separate value is
incorporated into the specification as if it were individually
recited herein. All methods described herein can be performed in
any suitable order unless otherwise indicated herein or otherwise
clearly contradicted by context. The use of any and all examples,
or exemplary language (e.g., "such as") provided herein, is
intended merely to better illuminate the invention and does not
pose a limitation on the scope of the invention unless otherwise
claimed. No language in the specification should be construed as
indicating any non-claimed element as essential to the practice of
the invention.
[0065] Preferred embodiments of this invention are described
herein, including the best mode known to the inventors for carrying
out the invention. Variations of those preferred embodiments may
become apparent to those of ordinary skill in the art upon reading
the foregoing description. The inventors expect skilled artisans to
employ such variations as appropriate, and the inventors intend for
the invention to be practiced otherwise than as specifically
described herein. Accordingly, this invention includes all
modifications and equivalents of the subject matter recited in the
claims appended hereto as permitted by applicable law. Moreover,
any combination of the above-described elements in all possible
variations thereof is encompassed by the invention unless otherwise
indicated herein or otherwise clearly contradicted by context.
* * * * *